EP-A-0 845 389 discloses a steering column switch with a housing, in which at least one operating lever is mounted to pivot and/or move, for which different types of operating levers with the corresponding contact device can be used during assembly. A mating contact device with a predefined number of switch functions that cooperates with the contact device of the operating lever is arranged in the housing of the steering column switch. The available choice of switch functions is a function of the type of operating lever to be installed and its contact device.
DE-A-43 32 748 also shows a steering column switch with a switch lever mounted to move, at least in one plane relative to the steering column, in a housing, which is in connection with switch elements arranged on a printed-circuit board for its activation. At least one of its switch elements is designed as a light-transmitting or light-receiving element in optical connection with a corresponding optical switch, operable by the switch lever.
DE 44 28 883 C1 discloses a steering column switch with a housing having mounts for single switches. The single switches comprise a switch housing, in which a switch lever is mounted to pivot. Guide elements are molded onto the switch housing for alignment in the correct position and holding in a mounting chamber of the housing. The switch housing also has clip elements for fastening of the switch in the corresponding mounting chambers. The switch is provided with function elements and is equipped with a printed-circuit board that is connected to a central circuit board of the steering column switch.
Steering column switches are also known, whose switches, integrated in a switch lever, are connected by corresponding wiring to a circuit board of the steering column switch, on which the switch lever is mounted in a two-part housing of the steering column switch, whose separation runs in the region of the switch lever. This type of switch lever must have corresponding free space available in its interior, in order to permit passage of the wiring, which requires relatively large dimensioning of the switch lever. Significant assembly expense is required for wiring within the switch lever, as well as from the switch lever to the corresponding circuit board. The steering column switches are pre-mounted together with the corresponding switch lever and then installed in the vehicle, so that a significant risk of damage to the switch lever exists during handling of the steering column switches.
The object of the invention is to devise a steering column switch of the initially mentioned type, which has various applications, in terms of functions, is inexpensive to manufacture and easy to handle during assembly.
The objective is realized according to the invention in that the switch lever is assembled from a foot cooperating with the switch element and a grip piece inserted into the foot.
Because of the two-part design of the switch lever, the switch mechanics of the steering column switch can be made cost effectively in a large number of pieces, regardless of its switching functions. Coordination of the switching functions to the steering column switch, provided with a central printed-circuit board, occurs by means of corresponding programming of the computer system of the vehicle. More specifically, the switch lever (grip piece) is coupled to the foot of the switch lever. Insertion of the grip piece into the foot can occur at the end of assembly of the steering column switch in the vehicle, for which reason the grip piece is only exposed to limited risk of damage during assembly. In addition, the arrangement of a one-part housing for the steering column switch is possible, which need only be provided with a corresponding opening for the grip piece. A visually pleasing effect is achieved with the one-part housing.
In a steering column switch of the initially mentioned type, with at least one additional switch integrated in the switch lever of the single switch, the objective according to the invention is realized in that the switch lever is assembled from a foot cooperating with the switch element and a grip piece inserted into the foot, wherein the end of the grip piece inserted into the foot has contact traces, which transmit the functions of the switch to the terminal contacts via a contact unit.
Because of these advantages, prefabrication of the switch mechanism of the steering column switch, together with the contact unit and the foot of the switch lever, is ensured in a relatively large number of pieces. Different grip pieces, insertable into the foot of the switch lever, each can be equipped with at least one arbitrarily designed switch. For example, a switch for interval functions of the windshield wiper is connected to the grip piece for a windshield wiper/washer switch. In addition or as an alternative, a switch to control a computer system is provided, in which the switch or switches cooperate with the contact traces integrated in the grip piece, and the electrical connection to the terminal contacts for the switch or switches is achieved by simple insertion of the grip piece into the foot over the contact unit.
In order to achieve rapid, permanent assembly, and also several degrees of freedom of the switch lever, the foot of the switch lever is preferably mounted as a swivel joint and provided with two opposite clip arms that engage in corresponding clip openings of the grip piece.
For simple swivel mounting of the switch lever and to achieve switching functions, the foot of the switch lever is expediently mounted to pivot in an opening of an arm of an L-shaped rotary switch element, where the rotary switch element is inserted into an arm of a Z-shaped support fixed to the housing. Arrangement of additional mounts with a switch lever therefore is unnecessary, since corresponding support sites are integrated in the rotary switch element.
The arm of the rotary switch element running parallel to the connector of the support is preferably provided with a terminating locating curved element that cooperates with a spring-loaded locating sleeve in the arm of the support facing the end of the rotary switch element. Thus, an initial position of the swivel-mounted switch lever is defined and a desired switching sensation is created during its operation. The arm of the support carrying the locating sleeve for the rotary switching element expediently comprises an additional spring-loaded locating sleeve that cooperates with a locating curve in the free end of the foot. Thus, the switch lever is held in a certain initial position. Pivoting of the switch lever from the initial position occurs against the spring force, to which the locating sleeve is exposed, so that a corresponding switch sensation is produced.
According to an advantageous modification of the invention, the arm of the support carrying the locating sleeves supports a sliding switch element, acted upon by the foot of the switch lever. The support therefore represents an essential component to accommodate the sliding switch element, as well as the rotary switch element, and forms a separate assembly with the connected switch element, which is simple to install and replace.
The switch contacts of the rotary switch element and the sliding switch element are expediently designed as contact springs and act on corresponding contact traces of the support that are connected to the terminal contacts. The contact springs are components of a punched grid inserted into the rotary switch element and the sliding switch element, which is simultaneously injection molded during production of the switch elements in the injection molding process, so that an additional assembly step can be eliminated. In order to avoid damage to the grip piece and the foot during assembly, the grip piece has a centering shoulder on the end inserted into the foot, which engages in a corresponding centering hole of the foot.
According to an advantageous embodiment of the concept of the invention, the contact traces of the grip piece are exposed regions of a punched grid integrated in the grip piece connected to the switch. Relatively costly wiring of the switch with the contact traces is therefore eliminated and a number of switching functions to be transmitted are possible by appropriate coding of the punched grid introduced to the grip piece.
In order to produce a cost-effective contact unit having relatively high functional safety and that ensures tolerance and movement compensation, the contact unit preferably has contact arms designed as leaf springs, where one end of each contact arm is connected to the corresponding contact trace of the punched grid of the grip piece and the other end of the contact arm is connected to a corresponding contact trace of the support. The contact arms of the contact unit that act on the contact traces of the support extend through a recess of the rotary switch element mounted in the support.
According to a modification of the invention, the contact unit has limiting arms on the side that extend essentially parallel to the contact arms. Each arm of the contact unit has a cylindrical shoulder on the end, where the opposite shoulders on one end of the contact unit engage in a corresponding recess of the rotary switch element and the shoulders on the other end of the contact unit engage in a corresponding recess of the foot. The contact unit therefore represents a compact assembly that can be fixed relatively simply between the rotary switch unit and the foot.
The recesses in the rotary switch element, in which the shoulders of the arm of the contact unit engage, are, advantageously, cylindrical holes. The recesses in the foot of the switch lever, into which the shoulders of the arm of the contact unit engage, are also elongated holes. In this way, a compensatory movement of the contact unit is guaranteed during the pivoting of the switch lever to act on the sliding switch element. The sliding of the contact arms of the contact unit on the corresponding contact traces of the grip piece and the contact traces of the support effects the self-cleaning of the support.
It is understood that the aforementioned features and those still to be explained can be used not only in the stated combination, but also in other combinations without departing from the scope of the present invention.